This invention relates to new formulations for finishing flat textiles based on esterquats and quatemized fatty acid imidazolines and to their use for conditioning fabrics and stabilizing them against yellowing.
The finishing of yarns and fabrics to the final textiles involves a complex requirement profile. The most important property which finishes are expected to show consists in providing textiles with a pleasant soft feel. Cationic surfactants are generally used for this purpose. Among these, esterquats are particularly important by virtue of their favorable ecological compatibility. Conditioning can be carried out both as a textile pretreatment and as an aftertreatment. Another requirement is to protect textiles against soiling, for which purpose polymers of the so-called xe2x80x9csoil repellantxe2x80x9d type are added to standard laundry aftertreatment products. A third important aspect is the stabilizing of fabrics against the effect of ozone which, in the case of blue denim in particular, leads very easily to yellowing. However, conventional conditioners do not satisfactorily meet this requirement.
Accordingly, the problem addressed by the present invention was to provide new conditioners which would enable flat textiles, i.e. yarns, woven fabrics and finished textiles, but especially blue denim cloth and jeans produced therefrom, to be given a pleasant soft feel and, at the same time, to be finished against yellowing.
The present invention relates to textile finishes containing
(a) esterquats and
(b) quaternized fatty acid imidazolines.
It has surprisingly been found that mixtures of esterquats and quaternized fatty acid imidazolines not only provide flat textiles and, preferably, blue denim cloth with a pleasant soft feel, they also reliably stabilize them against yellowing, particularly when the fatty acid part of component (b) is derived from oleic acid.
Esterquats
xe2x80x9cEsterquatsxe2x80x9d are generally understood to be quaternized fatty acid triethanolamine ester salts. They are known compounds which may be obtained by the relevant methods of preparative organic chemistry, cf. International patent application WO 91/01295 (Henkel), in which triethanolamine is partly esterified with fatty acids in the presence of hypophosphorous acid, air is passed through the reaction mixture and the whole is then quaternized with dimethyl sulfate or ethylene oxide. U.S. Pat. Nos. 3,915,867, 4,370.272, EP-A2 0 239 910, EP-A2 0 293 955 A2, EP-A2 0 295 739 and EP-A2 0 309 052 A2 are cited here as representative of the extensive prior-art literature. Overviews of this subject have been published, for example, by O. Ponsati in C.R. CED Congress, Barcelona, 1992, p. 167, by R. Puchta et al. in Tens. Surf. Det., 30, 186 (1993), by M. Brock in Tens. Surf. Det., 30, 394 (1993) and by R. Lagerman et al. in J. Am. Oil Chem. Soc., 71, 97 (1994).
The quaternized fatty acid triethanolamine ester salts correspond to formula (I): 
in which R1CO is an acyl group containing 6 to 22 carbon atoms, R2 and R3 independently of one another represent hydrogen or have the same meaning as R1CO, R4 is an alkyl group containing 1 to 4 carbon atoms or a (CH2CH2O)qH group, m, n and p together stand for 0 or numbers of 1to 12, q is a number of 1 to 12 and X is halide, alkyl sulfate or alkyl phosphate. Typical examples of esterquats which may be used in accordance with the present invention are products based on caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, isostearic acid, stearic acid, oleic acid, elaidic acid, arachic acid, behenic acid and erucic acid and the technical mixtures thereof obtained, for example, in the pressure hydrolysis of natural fats and oils. Saturated or predominantly saturated fatty acids, for example tallow or palm oil fatty acid, are preferably used. To produce the quaternized esters, the fatty acids and the triethanolamine may be used in a molar ratio of 1.1:1 to 3:1. With the performance properties of the esterquats in mind, a ratio of 1.2:1 to 2.2:1 and preferably 1.5:1 to 1.9:1 has proved to be particularly advantageous. The preferred esterquats are technical mixtures of mono-, di- and triesters with an average degree of esterification of 1.5 to 1.9 and are derived from tallow fatty acid. In performance terms, quatemized fatty acid triethanolamine ester salts corresponding to formula (I), in which R1CO is the acyl group of tallow fatty acid, R2 has the same meaning as R1CO, R3 is hydrogen, R4 is a methyl group, m, n and p stand for O and X stands for methyl sulfate, have proved to be particularly advantageous.
Besides the quaternized fatty acid triethanolamine ester salts, other suitable esterquats are quaternized ester salts of fatty acids with diethanol-alkyamines corresponding to formula (II): 
in which R1CO is an acyl group containing 6 to 22 carbon atoms, preferably an acyl group derived from tallow fatty acid, R2 is hydrogen or has the same meaning as R1CO, R4 and R5 independently of one another are alkyl groups containing 1 to 4 carbon atoms, m and n together stand for O or numbers of 1 to 12 and X stands for halide, alkyl sulfate or alkyl phosphate.
Finally, another group of suitable esterquats are the quaternized ester salts of fatty acids with 1,2-dihydroxypropyl dialkylamines corresponding to formula (III): 
in which R1CO is an acyl group containing 6 to 22 carbon atoms, preferably an acyl group derived from the fatty acid mixture containing tallow fatty acid, R2 is hydrogen or has the same meaning as R1CO, R4, R6 and R7 independently of one another are alkyl groups containing 1 to 4 carbon atoms, m and n together stand for O or numbers of 1 to 12 and X stands for halide, alkyl sulfate or alkyl phosphate.
So far as the optimal degree of esterification is concerned, the examples mentioned for (I) also apply to the esterquats corresponding to formulae (II) and (III). The esterquats are normally marketed in the form of 50 to 90% by weight solutions in alcohol which may readily be diluted as required with water.
Quaternized fatty acid imidazolines are also known cationic surfactants which are normally obtained by condensation of fatty acids with diamines, preferably ethylenediamines, and subsequent quaternization with alkyl halides or dialkyl sulfates. Processes for producing the imidazolines and their quaternization products are known, for example, from German references DE-A1 40 20 271, DE-A1 40 38 983 and DE-A1 41 16 648 (Henkel). The imidazolines may also contain open-chain hydrolysis products. However, they normally correspond to the following formula: 
in which R8 is an alkyl and/or alkenyl group containing 7 to 21 carbon atoms and preferably 11 to 17 carbon atoms, R9 represents optionally hydroxysubstituted alkyl groups containing 1 to 4 carbon atoms or a benzyl group, R10 represents hydroxysubstituted alkyl groups containing 2 to 4 carbon atoms or a CH2CH2NHCOR8 group and X stands for halide or alkyl sulfate. In one particular embodiment of the invention, products derived from oleic acid or from a fatty aced cut predominantly containing oleic acid are used. Quaternized fatty acid imidazolines obtained by condensation of oleic acid with diethylenetriamine or aminoethyl ethanolamine and subsequent quaternization with dimethyl sulfate or methyl chloride are particularly preferred. The ratio by weight of component (a) to component (b) in the textile finishes according to the invention may be from 90:10 to 10:90 and is preferably from 15:85 to 50:50 and more preferably, from 20:80 to 25:75.
The finishes according to the invention not only provide flat textiles, preferably blue denim cloth, with a pleasant soft feel, they also protect them reliably against yellowing. Accordingly, the present invention also relates to the use of the mixtures as finishes for simultaneously conditioning flat textiles and stabilizing them against yellowing. The finishes themselves are normally present in the form of aqueous solutions or pastes with an active substance content of 5 to 30% by weight. They may additionally contain electrolyte salts, for example, for adjusting viscosity.